A grizzly sow's survival in the modern world

Once upon a time there lived a sixyear-
old female grizzly bear. She was
beautiful, approaching 280 pounds,
mostly chocolate brown with lighter
shades dominating her forelegs and
her muscular shoulder hump. She
lived as all grizzlies do – solitary and
alone, wandering, in her case, the
wildest reaches of the Greater Yellowstone
Ecosystem.

She was fortunate. The majority of
her home range, almost 100 square
miles, was within Yellowstone
National Park. A smaller portion, her
fall range, extended northward into
the adjoining Absaroka-Beartooth
Wilderness. With the exception of
fall hunting season and chance en –
counters with vehicular traffic, she
was safe from human encounters –
and hence human-caused mortality.

In the spring she became pregnant.
But a successful pregnancy requires
a successful feeding season, and last
fall the whitebark pine nut crop,
a food source critical to Yellowstone’s
grizzlies, had failed. In a
compromised state, as indicated by
her marginal stored-fat layer, she
aborted the pregnancy.

So again she had attracted three
different adult male grizzlies whose
home ranges overlapped hers. Their
big, sensitive noses scented her
from more than a mile away. They
postured and fought, and eventually
a massive 15-year-old boar
weighing nearly 600 pounds was
chosen. The courtship lasted several
weeks – from late May through
the third week in June. She gave
birth to three small cubs approxi –
mately nine months later.

The three cubs, born in the solitude
and quiet of the winter den, were
tiny at birth. Two males and one female,
they were born in late-January,
weighing approximately 16 ounces.
One pound. Naked, hairless and
totally dependent on their mother for
the first few months of their lives.
That dependency can, in the best
circumstances, last upwards of three
years.

Thus, in a quiet den, near tree line
in the remote northern reaches of
Yellowstone, it began for this family
of bears. Upon emergence in early
April, the cubs’ known world grew
exponentially. And so, too, did the
potential for trouble. Toward the
end of May, one of the male cubs
drowned while crossing a stream
swollen with snowmelt.

In August, at the height of the tourist
season, a car in the Lamar Valley
hit and killed the female cub. The
remaining male survived the gauntlet
that first year and by late fall weighed
90 pounds. He and the sow entered a
den at the end of the feeding season,
in November.

Once more, with the pull of spring
they emerged, this year in mid-
March. Spring came early to the
Northern Rockies. Upon emergence
and driven by a relentless hunger,
they migrated down-slope to valley
bottoms, just beginning to free from
snow and likely to offer succulent
plants which make up the bulk of a
grizzly’s diet.

In April, the sow located an elk carcass
abandoned by a pack of wolves.
As a matter of survival, this early
season abundance of calories had to
be investigated.

But two days earlier, just after the
elk was killed, a male grizzly had
claimed the kill as his own, pushing
off the 10 wolves. As the sow and
cub neared, the female scented his
presence. She could not; however,
determine his exact location. Cautiously,
they moved in to feed on the
carcass. It would prove a fatal mistake
for her surviving cub.

The big male grizzly, asleep in a nearby
cover of thick vegetation, quickly
responded to the trespass. Moving
at 30 miles an hour, he covered 150
yards to the elk carcass in 10 seconds.
The young male cub was caught from
behind, and he died instantly with a
powerful bite to the neck.

Had the female time to respond,
perhaps she could have intervened
and saved her cub. Regardless, she
was again on her own, her three cubs
gone.

Her fate would be determined,
as always, by her ability to locate
adequate calories and stay out of
harm’s way. In most cases, this means
avoiding humans. She might live to
age 20 and reach 600 pounds. She
would, as the spring seasons arrived
over the years, attract males, mate
and produce cubs. If all went well, a
small number of those, perhaps two
or three, would survive to become
breeding-age adults themselves.

Grizzlies live within well-defined
and relatively rigid biological parameters.
In the long-term game of
survival, these limitations are compounded
by today’s modern world.

Greg Smith worked for nearly 20 summers
in Glacier National Park as a
ranger naturalist and a backcountry/
bear management ranger. Those years
re-affirmed his belief that education is
one of the key roles a ranger can play
in a place such as Glacier. He “talked
bears” to thousands of backcountry
users over the years. Not once did he
have to “manage” a bear. Such is bear
management, when done correctly.